FOREST LANDS FOE THE PROTECTION OF WATERSHEDS. 109 



problem which arise from the fact that the effect of the forests can not be sep- 

 arated from the other elements entering into the problem. 



Similarly inconclusive is the statement about the flood of the American river 

 compared with Puta Creek in California. Watersheds differ not alone as re- 

 gards forests, but in other respects. The facts stated simply seem to show that 

 in this case the forests did not regulate its-flow to an extent sufficient to coun- 

 terbalance other factors. For instance, if the writer is correctly informed, the 

 slopes of the Sierras are steeper than those of the coast range. Again, the 

 shape of the drainage area is a matter of considerable importance with reference 

 to the maximum rise of water at a given point. 



The writer has not had the opportunity to study to any extent the conditions 

 in the Rocky Mountains, but he observes that Prof. L. G. Carpenter, of the Col- 

 orado State Agricultural College than whom there is no more competent au- 

 thority in his paper on " Forest and snow " comes to the conclusion that 

 (a) * * * " the greater the amount of forest cover the less violent the daily 

 fluctuation, the more uniform the flow throughout the day and throughout the 

 season and the later the stream maintains its flow. (&) The loss of the forest 

 cover means more violent fluctuation during the day, greater difficulty in regu- 

 lating the head gates and keeping a uniform flow in ditches, and 'hence an 

 additional difficulty in the economic distribution of water; also the water runs 

 off sooner, hence the streams drop earlier in the summer, and, on account of the 

 lessening of the springs, the smaller is the winter flow, (c) The preservation 

 of the forest is an absolute necessity for the interest of irrigated agriculture." 



Colonel Chittenden, however, after devoting so much space to considering the 

 effects of forests upon extremes of flow, does not on the whole take his own 

 arguments seriously, for later on he says : " In the records of precipitation, 

 wherever they exist, will be found a full and complete explanation of every one 

 of the floods that have seemed unusually frequent and severe in recent years." 

 After citing the conditions, he goes on to say : " Similar conditions prevail in 

 every great flood, and the true explanation is found in them and not at all in 

 the presence or absence of forests on the watersheds." 



Reference has already been made to the fact that the amount and distribu- 

 tion of rainfall are the most important factors affecting the flow of streams, 

 yet it is quite unreasonable to conclude that on that account the forests have 

 no effect at all. 



These quotations are cited, however, to show the apparent contradictions in 

 Colonel Chittenden's arguments. 



It would' take too long to analyze in detail the remainder of Colonel Chit- 

 tenden's paper and to criticize his many statements. If his views, however, 

 have weight, attention should be called to one statement which he makes with 

 reference to erosion. He states (page 955 et seq. ) that the sediment carried 

 into the Gulf of Mexico by the Mississippi " all comes from the uplands far 

 ;ind near, but particularly from the more remote and hilly regions. This load 

 is in the nature of through traffic. The local freight picked up from a caving 

 bank is mainly discharged at the next station. It follows, therefore, that if the 

 banks of a stream were revetted from the Gulf to Pittsburg, the Falls of St. 

 Anthony and the mouth of the Yellowstone, the quantity of sediment passing 

 into the Gulf would not be diminished a particle." 



As the quantity of sediment carried into the Gulf each year is exceedingly 

 large. Colonel Chittenden admits the great erosion from the mountain slopes. 

 \Ve do not agree with him, however, in the statement quoted. A river picks 

 up sediment where the velocity of the water and the size of the grains of sedi- 

 ment admit, and a reduction of velocity causes the deposition of sediment, be- 

 ginning with the heaviest particles. The river cuts away a bank here and de- 

 posits a bar there, and much of its load is, as Colonel Chittenden states, in the 

 nature of local freight. The important point, however, is that all this freight 

 is moving downstream, and it would seem scarcely reasonable to suppose that 

 under this continual movement downstream the only silt to find its way into 

 the Gulf .is that which comes from the extreme sources. 



In contradiction to the above statements. Colonel Chittenden says: "It is 

 incontestably true that whatever restraining effect forests have upon run-off is 

 greater upon the lowlands than upon steep mountain sides." This is a good 

 illustration of the character of statement with which this paper abounds, posi- 

 tive statements given entirely without proof and in contradiction to all experi- 

 ence and to the best authorities. It would seem to be reasonably clear that 

 since on steep slopes there is more tendency for the water to run off than on 

 moderate slopes and flat land, whatever restraining effect the forest exerts 



